Theme 2-6-Analysis of arsenic contaminated groundwater domain in Nadia district of West Bengal

Abstract

The paper presents an analysis of groundwater flow and transport process of Arsenic in the flow domain of Yamuna sub-basin located in the Nadia and North 24 Parganas districts of West Bengal. The objectives of the analysis are :1. Conceptualisation of the groundwater flow domain, 2. De- termination of groundwater flow paths and groundwater velocities, 3. Study of ARSENIC trans- port in the flow domain. 4. Study of Well capture zones. First three objectives and issues are addressed by simulation of steady and transient state of groundwater flow and contaminant trans- port using .United States Geological Survey (USGS) developed three - dimensional finite differ- ence code MODFLOW and three - dimensional advective - dispersive transport code MT3D. Calibrated model replicate the observed transient water table conditions perfectly. Contaminant transport analysis indicates in-situ Arsenic source. Using particle tracking algorithm MODPATH, possibility of Arsenic removal from a sample key location, and design of wells for withdrawing Arsenic free groundwater have been studied through analysis of well capture zones.